Thalamus

Name 2 parts of the association cortex.

pre frontal cortex, parietal-occipital-temporal cortex

Dorsal medial nucleus is connected extensively to the ____ and receives input from limbic structures such as the amygdala. Could possibly be involved in emotions and foresight.

prefrontal cortex

The association cortex is the cerebral cortex outside the __ areas.

primary

Thalamic projection neurons can exist in which 2 physiological states?

tonic and burst mode

What do medullary lamina do?

transmit info between thalamic nuclei and to and from the thalamus

Name some charcateristics/results of thalamic neurons in 'burst mode'.

use during sleep, doesnt transmit sensory info to cortex faithfully, induced by GABAergic input from RTN neurons, large and synchronized waves on electroencephalogram

Name some characteristics/results of thalamic neurons in 'tonic mode'.

used when awake, faithfully transmits sensory info from other neurons to cortex, induced by 5HT, NE, ACh, cortical input, opposes hyperpolarization of relay neurons, rapid/desynchronized alpha waves

The hippocampus receives input from all other limbic structures via the ___. Name some examples of limbic structures.

fornix; amygdala, hypothalamus, septal nuclei

The 4 parts of the thalamus are called ?

hypothalamus, epithalamus, subthalamus, thalamus

In a coronal section, what structure can be seen flanking the thalamus?

internal capsule

Explain how rhythmic burst firing of relay neurons work in relation to reticular thalamic nucleus cells.

1. RTN neurons (GABAergic) fire APs, which hyperpolarizes relay neurons. 2. When RTN neurons stop firing, relay neurons undergo burst rebound firing. 3. Burst of APs travels down relay neuron collateral axon and induces a RTN to fire a burst of APs, and cycle continues to repeat itself.

Thalamus is located centrally in the brain, on either side of the ____, just below the lateral ventricles.

3rd ventricles

Reticular thalamic nuerons are ___ergic and project mainly to thalamic nuclei to modulate relay neuron activity.

GABA

Nonspecific thalamic nuclei include the ____ and ____ nuclei.

Intralaminar and midline nuclei

The pulvinar receives input from the ___, ___ and other areas and projects to the visual association cortex.

Lateral geniculate body, superior colliculis

Name the association nuclei.

Pulvinar and medial dorsal nucleus

Nonspecific thalamic nuclei may be involved in ____. They also have connections to limbic structures and basal ganglia, which suggest additional roles.

arousal and alertness

Name a major relay center for information coming form limbic structures, and that recieves info from the entire limbic system, be it indirectly or directly.

anterior thalamic nucleus

Sensory relay nuclei transmit info to the somatosensory cortex. Motor relay nuclei transmit info from the ___ and ____ to motor areas of the cortex.

cerebellum and basal ganglia

Mammillary bodies send projections to the anterior thalamic nucleus, which projects largely to the ___.

cingulate gyrus

This structure plays a role in higher order analysis and reactions to input from the limbic system.

cingulate gyrus

The thalamus is the largest part of the ___.

diecephalon

The grey matter making up the thalamic nuclei is divided into anterior, lateral and medial divisions. What separates these divisions?

internal medullary laminae

The ____ receives inputs from various components of the limbic system (hippocampus, amygdala, hypothalamus) and projects to the cingula te and prefrontal cortex.

medial dorsal nucleus

The thalamus is the primary relay site for all sensory pathways to the cerebral cortex, except for __ signals, which have a direct connection to the cortex.

olfactory

The pulvinar is extensively connected with the ____ and receives additional input from parts of the visual system.

parietal-occipital-temporal cortex

The medial geniculate body receives what type of input and projects where?

receives auditory input and projects to primary auditory cortex

The lateral geniculate body receives what type of input and projects where?

receives visual input and projects to the primary visual cortex

Relay thalamic nuclei are connected with relay neurons in a loop that can reinforce rhythmic burst firing of ___.

relay neurons

Name the 4 major categories of thalamic nuclei.

relay nuclei, association nuclei, nonspecific nuclei, reticular thalamic nuclei

The ___ is separated from the thalamus laterally via the external medullary lamina.

reticular nucleus

Name the 3 subdivisions within relay nuclei.

sensory relay nuclei, motor relay nuclei, limbic relay nuclei

Name the sensory relay nuclei.

sensory- VPM and VPL nuclei, lateral & medial geniculate nuclei Motor- VA and VL Limbic- anterior thalamic

The ___ receives somatosensory information from the trunks/limbs and projects to somatosensory cortex. May use connections such as the spinothalamic tract and the medial lemniscus.

ventraposterolateral nucleus

The ___ and ___ receive input from the cerebellum and basal ganglia to project to the pre-motor and primary cortex.

ventroanterior (VA) and ventrolateral (VL)

The ___ receives somatosensory information from the head and projects to the somatosensory cortex. May use connections such as the spinothalamic tract and the medial meniscus.

ventroposteromedial

How does each cortical area filter incoming information?

via regulatory inputs back to corresponding thalamic nucleus